Schizophrenia and Other Psychotic Disorders

The disorders in this section include Schizophrenia, Schizophreniform Disorder, Schizoaffective Disorder, Delusional Disorder, Brief Psychotic Disorder, Shared Psychotic Disorder, Psychotic Disorder Due to a General Medical Condition, SubstanceInduced Psychotic Disorder, and Psychotic Disorder NotOtherwise Specified. These disorders have been grouped together' to facilitate the differential diagnosis of disorders that include psychotic symptoms as a prominent aspect of their presentation. Other disorders that may present with psychotic symptoms as associated·features are included elsewhere in the manual (e.g., Dementia of the Alzheimer's Type and Substance-Induced Delirium in the "Delirium, Dementia, and Amnestic and Other Cognitive Disorders" section; Major Depressive Disorder, With Psychotic Features, in the "Mood Disorders" section). Despite the fact that these disorders are grouped together in this chapter, it should be understood that psychotic symptoms are not necessarily considered to be core or fundamental features of these disorders, nor do the disorders in this section necessarily have a common etiology. In fact, a number of studies suggest closer etiological associations between Schizophrenia and other diSorders that, by definition, do not present with psychotic symptoms (e.g., Schizotypal Personality Disorder) .. The term psychotic has historically received a number of different definitions, none of which has achieved universal acceptance. The narrowest definition of psychotic is restricted to delusions or prominent hallucinationS, with the hallucinations occurring in the absence of insight into their pathological nature. A slightly less restrictive definition would also include prominent hallucinations that the·individual realizes are hallucinatory experiences. Broader still is a definition that also includes other positive symptoms of Schizophrenia (Le., ~organized speech, grossly disorganized or catatonic behavior). Unlike these definitions I,>asedon symptoms, the definition used in earlier classifications (e.g., DSM-ll arid ICD-9fwas probably far too inclusive and focused or the severity of functional impairment In that context, a mental disorder was termed "psychotic" if it resUlted in "impairment that grossJy interferes with the capacity to meet ordinarydeinands of life." The term has also.previouslybeen defined as a ,"loss of ego boundaries" or a "gross impairmentinreality testing." .' . .In this manual, the term psychotic refers to the presence of certain symptoms. However, the specific constellation of symptoms to which the term refers varies to some extent across the diagnostic categories. In Schizophrenia, Schizophreniform Disorder, Schizoaffective DisOrder, and Brief Psychotic Disorder, the term psychotic refers to delusions, any prominent hallucinations, disorganized speech, or disorganized or catatonic behavior. In Psychotic Disorder Due to a General Medical Condition and in